Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760403AbcCDWra (ORCPT ); Fri, 4 Mar 2016 17:47:30 -0500 Received: from mail-pa0-f46.google.com ([209.85.220.46]:33488 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759277AbcCDWr2 (ORCPT ); Fri, 4 Mar 2016 17:47:28 -0500 From: Bill Sommerfeld To: "David S. Miller" Cc: Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy , Josh Hunt , Benjamin LaHaise , Eric Dumazet , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Bill Sommerfeld Subject: [PATCH] udp6: fix UDP/IPv6 encap resubmit path Date: Fri, 4 Mar 2016 14:47:21 -0800 Message-Id: <1457131641-79311-1-git-send-email-wsommerfeld@google.com> X-Mailer: git-send-email 2.7.0.rc3.207.g0ac5344 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1219 Lines: 36 IPv4 interprets a negative return value from a protocol handler as a request to redispatch to a new protocol. In contrast, IPv6 interprets a negative value as an error, and interprets a positive value as a request for redispatch. UDP for IPv6 was unaware of this difference. Change __udp6_lib_rcv() to return a positive value for redispatch. Note that the socket's encap_rcv hook still needs to return a negative value to request dispatch, and in the case of IPv6 packets, adjust IP6CB(skb)->nhoff to identify the byte containing the next protocol. Signed-off-by: Bill Sommerfeld --- net/ipv6/udp.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 0711f8f..fd25e44 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -922,11 +922,9 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, ret = udpv6_queue_rcv_skb(sk, skb); sock_put(sk); - /* a return value > 0 means to resubmit the input, but - * it wants the return to be -protocol, or 0 - */ + /* a return value > 0 means to resubmit the input */ if (ret > 0) - return -ret; + return ret; return 0; } -- 2.7.0.rc3.207.g0ac5344